Approach To Typicality In Quantum Systems,
2011
University of Massachusetts Boston
Approach To Typicality In Quantum Systems, Shawn Dubey
Applied Physics Masters Theses Collection
The study of quantum mechanics has greatly broadened since its inception in the early twentieth century. Recent research has focused on the emergence of thermalization in quantum many-body systems. In this thesis I will demonstrate the approach to typicality--the notion that for specific sets of objects, most of the objects share a common property--in a single, many-body spins chain of spin half particles. This notion of typicality is new. But it serves as a good explanation for the emergence of thermalization.
Quantum Mechanics, Quantum Computation, And The Density Operator In Sympy,
2011
California Polytechnic State University - San Luis Obispo
Quantum Mechanics, Quantum Computation, And The Density Operator In Sympy, Addison Cugini
Physics
Because aspects of quantum mechanics are both difficult to understand and difficult algebraically, there is a need for software which symbolically simulates quantum mechanical phenomena. To accomplish this goal, code has been added to an open-source computer algebra system, called SymPy, which models the abstraction of Dirac notation and the density operator. Additionally, a quantum computer simulation has been built using this abstraction. This paper shall discuss the code that has been added as well as any relevant physics important to understanding the code. In particular, we shall focus on the density operator of statistical quantum mechanics using SymPy's density …
Symbolic Quantum Circuit Simplification In Sympy,
2011
California Polytechnic State University - San Luis Obispo
Symbolic Quantum Circuit Simplification In Sympy, Matthew Curry
Physics
In the field of quantum information science, one can design a series of quantum logic operations known as a circuit. Circuits are the basis for quantum computations in quantum computing. As circuits will most likely be designed from a logical standpoint, there could exist mathematical redundancies which will lead to a larger circuit than necessary. These redundancies are computationally expensive, and there is a need for them to be found and eliminated to simplify the circuit. We present our research on finding the rules for simplifying circuits and its implementation in SymPy.
Quantum Ghost Imaging Through Turbulence,
2011
Chapman University
Quantum Ghost Imaging Through Turbulence, John C. Howell
Mathematics, Physics, and Computer Science Faculty Articles and Research
We investigate the effect of turbulence on quantum ghost imaging. We use entangled photons and demonstrate that for a specific experimental configuration the effect of turbulence can be greatly diminished. By decoupling the entangled photon source from the ghost-imaging central image plane, we are able to dramatically increase the ghost-image quality. When imaging a test pattern through turbulence, this method increases the imaged pattern visibility from V=0.15±0.04 to 0.42±0.04.
The Quantum Dialectic,
2011
Pitzer College
The Quantum Dialectic, Logan Kelley
Pitzer Senior Theses
A philosophic account of quantum physics. The thesis is divided into two parts. Part I is dedicated to laying the groundwork of quantum physics, and explaining some of the primary difficulties. Subjects of interest will include the principle of locality, the quantum uncertainty principle, and Einstein's criterion for reality. Quantum dilemmas discussed include the double-slit experiment, observations of spin and polarization, EPR, and Bell's theorem. The first part will argue that mathematical-physical descriptions of the world fall short of explaining the experimental observations of quantum phenomenon. The problem, as will be argued, is framework of the physical descriptive schema. Part …
Holism And Non-Separability Applied To Quantum Mechanics,
2011
James Madison University
Holism And Non-Separability Applied To Quantum Mechanics, Catherine E. Nisson
Senior Honors Projects, 2010-2019
Einstein was never satisfied with quantum mechanics. He argued that quantum mechanics was incomplete for two main reasons; it violated the locality principle and the separability principle. The violation of separability is an unavoidable consequence of quantum interactions. Non-separability can be seen in quantum entanglement. Non-locality, however, is more controversial. Einstein and his associates published the EPR paper in order to argue for the incompleteness of quantum mechanics. Years later, John Bell formulated what became known as the Bell Inequalities in response to the EPR paper. The Bell Inequalities are seen as a major obstacle for quantum locality. I will …
Prioritizing Investment In Residential Energy Efficiency And Renewable Energy: A Case Study For The U.S. Midwest,
2011
University of Dayton
Prioritizing Investment In Residential Energy Efficiency And Renewable Energy: A Case Study For The U.S. Midwest, Robert J. Brecha, Austin Mitchell, Kevin P. Hallinan, J. Kelly Kissock
Physics Faculty Publications
Residential building energy use is an important contributor to greenhouse gas emissions and in the United States represents about 20% of total energy consumption. A number of previous macro-scale studies of residential energy consumption and energy-efficiency improvements are mainly concerned with national or international aggregate potential savings. In this paper we look into the details of how a collection of specific homes in one region might reduce energy consumption and carbon emissions, with particular attention given to some practical limits to what can be achieved by upgrading the existing residential building stock. Using a simple model of residential, single-family home …
Entangling The Lattice Clock With Rydberg Gates,
2011
University of Nevada, Reno
Entangling The Lattice Clock With Rydberg Gates, Frank J. Greenhalgh
Festival of Communities: UG Symposium (Posters)
Knowledge of the exact time is critical to many engineers and planetary experts; unfortunately atomic clocks can't have infinite accuracy by Heisenberg's uncertainty principle. To attain accuracy past the limit we have achieved today, we will design a critical improvement of the atomic clock via the Rydberg gates method. Rydberg gates synchronize the atomic states so that they are more sensitive which will greatly increase the accuracy. This project will introduce fast acting Rydberg gates to an existing atomic clock layout. The Rydberg gates will allow the clock to entangle atoms in less time, thus decreasing decoherence effects on the …
“Magic” Trapping Of Rydberg States For Quantum Information,
2011
University of Nevada, Reno
“Magic” Trapping Of Rydberg States For Quantum Information, Muir Morrison, Andrei Derevianko
Festival of Communities: UG Symposium (Posters)
Recent experiments using neutral atoms to manipulate quantum information show promise for constructing a large-scale, practical quantum computer. Achieving such a quantum computer will require less destructive optical traps for the atoms. Using theoretical and computational tools, we consider the feasibility of one possible “magic” trap for rubidium. Preliminary results suggest such trapping may be possible, but more accurate calculations are necessary to reach definitive conclusion.
Dynamical Critical Scaling And Effective Thermalization In Quantum Quenches: Role Of The Initial State,
2011
Dartmouth College
Dynamical Critical Scaling And Effective Thermalization In Quantum Quenches: Role Of The Initial State, Shusa Deng, Gerardo Ortiz, Lorenza Viola
Dartmouth Scholarship
We explore the robustness of universal dynamical scaling behavior in a quantum system near criticality with respect to initialization in a large class of states with finite energy. By focusing on a homogeneous XY quantum spin chain in a transverse field, we characterize the nonequilibrium response under adiabatic and sudden quench processes originating from a pure as well as a mixed excited initial state, and involving either a regular quantum critical or a multicritical point. We find that the critical exponents of the ground-state quantum phase transition can be encoded in the dynamical scaling exponents despite the finite energy of …
Quantum Mechanical Model Of The Hydrogen Atom,
2011
Department of Mathematical Sciences, University of Texas at El Paso
Quantum Mechanical Model Of The Hydrogen Atom, Andres Ortiz^, Snehanshu Saha*
COURI Symposium Abstracts, Spring 2011
The quantum mechanical wave function of an object under a certain potential is determined by the Schrödinger equation. It is known that the latter equation can be solved analytically only for a finite number of distinct potentials, being a Coulomb potential one of them. For an electron in a hydrogen atom, we analytically find the angular parts of its wave function by the usual method. Under the appropriate change of variable, the radial part of the equation is turned into a Legendre differential equation whose solutions are Legendre polynomials. Using finite difference method and shooting method taking into account physically …
Modeling Of Solvent Electrostatic Effects,
2011
Department of Physics, University of Texas at El Paso
Modeling Of Solvent Electrostatic Effects, Jose A. Rodriguez Lopez^, Luis Basurto, Tunna Baruah*
COURI Symposium Abstracts, Spring 2011
The photo-induced charge-transfer process is fundamental to light harvesting in organic donor-acceptor systems. The process is often enhanced when the system is in a polar solvent. The aim of this project is to create a simple, discrete model containing dipoles that can explain the solvent effects, where only dipole-dipole solvent interaction is considered. The goal is to reduce computational complexities and cost. We create a grid of solvents (water) which mimic the solvent’s density; and put one solute (a light-harvesting triad of β-carotene, porphyrin, and C60) at the grid’s center, keeping the grid points 1.5 times the Van der Waal …
Coherent-State Transfer Via Highly Mixed Quantum Spin Chains,
2011
Massachusetts Institute of Technology
Coherent-State Transfer Via Highly Mixed Quantum Spin Chains, Paola Cappellaro, Lorenza Viola, Chandrasekhar Ramanathan
Dartmouth Scholarship
Spin chains have been proposed as quantum wires in many quantum-information processing architectures. Coherent transmission of quantum information in spin chains over short distances is enabled by their internal dynamics, which drives the transport of single-spin excitations in perfectly polarized chains. Given the practical challenge of preparing the chain in a pure state, we propose to use a chain that is initially in the maximally mixed state. We compare the transport properties of pure and mixed-state chains and find similarities that enable the experimental study of pure-state transfer via mixed-state chains. We also demonstrate protocols for the perfect transfer of …
Experimental Violation Of Two-Party Leggett-Garg Inequalities With Semiweak Measurements,
2011
Chapman University
Experimental Violation Of Two-Party Leggett-Garg Inequalities With Semiweak Measurements, Justin Dressel, C. J. Broadbent, J. C. Howell, Andrew N. Jordan
Mathematics, Physics, and Computer Science Faculty Articles and Research
We generalize the derivation of Leggett-Garg inequalities to systematically treat a larger class of experimental situations by allowing multiparticle correlations, invasive detection, and ambiguous detector results. Furthermore, we show how many such inequalities may be tested simultaneously with a single setup. As a proof of principle, we violate several such two-particle inequalities with data obtained from a polarization-entangled biphoton state and a semiweak polarization measurement based on Fresnel reflection. We also point out a nontrivial connection between specific two-party Leggett-Garg inequality violations and convex sums of strange weak values.
Equivalent Dynamical Complexity In A Many-Body Quantum And Collective Human System,
2011
University of Miami
Equivalent Dynamical Complexity In A Many-Body Quantum And Collective Human System, Neil F. Johnson, Josef Ashkenazi, Zhenyuan Zhao, Luis Quiroga
Physics Articles and Papers
Proponents of Complexity Science believe that the huge variety of emergent phenomena observed throughout nature, are generated by relatively few microscopic mechanisms. Skeptics however point to the lack of concrete examples in which a single mechanistic model manages to capture relevant macroscopic and microscopic properties for two or more distinct systems operating across radically different length and time scales. Here we show how a single complexity model built around cluster coalescence and fragmentation, can cross the fundamental divide between many-body quantum physics and social science. It simultaneously (i) explains a mysterious recent finding of Fratini et al. concerning quantum many-body …
Establishing Building Recommissioning Priorities And Potential Energy Savings From Utility Energy Data,
2011
University of Dayton
Establishing Building Recommissioning Priorities And Potential Energy Savings From Utility Energy Data, Kevin P. Hallinan, Philip Brodrick, Jessica Northridge, J. Kelly Kissock, Robert J. Brecha
Physics Faculty Publications
An energy reduction program for commercial buildings is implemented for a SW Ohio natural gas utility. The aim of this study is to demonstrate that historical utility data for individual building customers, along with knowledge of pertinent building information (square footage, year built, number of floors, height of floors, wall construction type, and use type) available in county auditor databases, could be used to identify the best candidate buildings for recommissioning in terms of energy savings and simple payback. A study is completed for all natural gas customers of a utility in Montgomery and Clinton counties in Ohio. A total …
Stern-Gerlach Dynamics With Quantum Propagators,
2011
Brigham Young University
Stern-Gerlach Dynamics With Quantum Propagators, Bailey C. Hsu, Manuel Berrondo, Jean F. Van Huele
Faculty Publications
We study the quantum dynamics of a nonrelativistic neutral particle with spin in inhomogeneous external magnetic fields. We first consider fields with one-dimensional inhomogeneities, both unphysical and physical, and construct the corresponding analytic propagators. We then consider fields with two-dimensional inhomogeneities and develop an appropriate numerical propagation method. We propagate initial states exhibiting different degrees of space localization and various initial spin configurations, including both pure and mixed spin states. We study the evolution of their spin densities and identify characteristic features of spin density dynamics, such as the spatial separation of spin components, and spin localization or accumulation. We …
Superluminal Neutrinos At Opera Confront Pion Decay Kinematics,
2011
Washington University in St Louis
Superluminal Neutrinos At Opera Confront Pion Decay Kinematics, Ramanath Cowsick, Shmuel Nussinov, Utpal Sarkar
Mathematics, Physics, and Computer Science Faculty Articles and Research
Violation of Lorentz invariance (VLI) has been suggested as an explanation of the superluminal velocities of muon neutrinos reported by OPERA. In this Letter, we show that the amount of VLI required to explain this result poses severe difficulties with the kinematics of the pion decay, extending its lifetime and reducing the momentum carried away by the neutrinos. We show that the OPERA experiment limits alpha = (upsilon(v) - c)/c < 4 x 10(-6). We then take recourse to cosmic-ray data on the spectrum of muons and neutrinos generated in Earth's atmosphere to provide a stronger bound on VLI: (upsilon - c)/c < 10(-12).
Poincare Recurrence And Spectral Cascades In Three-Dimensional Quantum Turbulence,
2011
Old Dominion University
Poincare Recurrence And Spectral Cascades In Three-Dimensional Quantum Turbulence, George Vahala, Jeffrey Yepez, Linda L. Vahala, Min Soe, Bo Zhang, Sean Ziegeler
Electrical & Computer Engineering Faculty Publications
The time evolution of the ground state wave function of a zero-temperature Bose-Einstein condensate (BEC) gas is well described by the Hamiltonian Gross-Pitaevskii (GP) equation. Using a set of appropriately interleaved unitary collision-stream operators, a qubit lattice gas algorithm is devised, which on taking moments, recovers the Gross-Pitaevskii (GP) equation under diffusion ordering (time scales as length2). Unexpectedly, there is a class of initial states whose Poincaré recurrence time is extremely short and which, as the grid resolution is increased, scales with diffusion ordering (and not as length3). The spectral results of J. Yepez et al. …
Dynamical Features Of Interference Phenomena In The Presence Of Entanglement,
2011
Tel Aviv University
Dynamical Features Of Interference Phenomena In The Presence Of Entanglement, Tirzah Kaufherr, Yakir Aharonov, Shmuel Nussinov, Sandu Popescu, Jeff Tollaksen
Mathematics, Physics, and Computer Science Faculty Articles and Research
A strongly interacting, and entangling, heavy nonrecoiling external particle effects a significant change of the environment. Described locally, the corresponding entanglement event is a generalized electric Aharonov-Bohm effect, which differs from the original one in a crucial way. We propose a gedanken interference experiment. The predicted shift of the interference pattern is due to a self-induced or "private" potential difference experienced while the particle is in vacuum. We show that all nontrivial Born-Oppenheimer potentials are "private" potentials. We apply the Born-Oppenheimer approximation to interference states. Using our approach, we calculate the relative phase of the external heavy particle as well …
